cse.c (notreg_cost): New argument outer.

* cse.c (notreg_cost): New argument outer.
        (COST): Pass in SET to notreg_cost
        (COST_IN): New.
        (fold_rtx): Use COST_IN.  Prefer constants when costs
        are the same.

From-SVN: r36671
This commit is contained in:
Richard Henderson 2000-09-29 16:22:20 -07:00 committed by Richard Henderson
parent 99eaf8d457
commit f2fa288f03
2 changed files with 29 additions and 10 deletions

View File

@ -1,3 +1,11 @@
2000-09-29 Richard Henderson <rth@cygnus.com>
* cse.c (notreg_cost): New argument outer.
(COST): Pass in SET to notreg_cost
(COST_IN): New.
(fold_rtx): Use COST_IN. Prefer constants when costs
are the same.
2000-09-29 David Edelsohn <edelsohn@gnu.org>
* fixinc/inclhack.def (broken_cabs): Generalize regex.

View File

@ -502,7 +502,8 @@ struct table_elt
|| ((N) < FIRST_PSEUDO_REGISTER \
&& FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS))
#define COST(X) (GET_CODE (X) == REG ? 0 : notreg_cost (X))
#define COST(X) (GET_CODE (X) == REG ? 0 : notreg_cost (X, SET))
#define COST_IN(X,OUTER) (GET_CODE (X) == REG ? 0 : notreg_cost (X, OUTER))
/* Get the info associated with register N. */
@ -636,7 +637,7 @@ struct cse_basic_block_data
|| XEXP (X, 0) == virtual_outgoing_args_rtx)) \
|| GET_CODE (X) == ADDRESSOF)
static int notreg_cost PARAMS ((rtx));
static int notreg_cost PARAMS ((rtx, enum rtx_code));
static int approx_reg_cost_1 PARAMS ((rtx *, void *));
static int approx_reg_cost PARAMS ((rtx));
static int preferrable PARAMS ((int, int, int, int));
@ -800,8 +801,9 @@ preferrable (cost_a, regcost_a, cost_b, regcost_b)
from COST macro to keep it simple. */
static int
notreg_cost (x)
notreg_cost (x, outer)
rtx x;
enum rtx_code outer;
{
return ((GET_CODE (x) == SUBREG
&& GET_CODE (SUBREG_REG (x)) == REG
@ -813,7 +815,7 @@ notreg_cost (x)
&& TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)),
GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x)))))
? 0
: rtx_cost (x, SET) * 2);
: rtx_cost (x, outer) * 2);
}
/* Return an estimate of the cost of computing rtx X.
@ -3752,7 +3754,7 @@ fold_rtx (x, insn)
/* Pick the least expensive of the folded argument and an
equivalent constant argument. */
if (const_arg == 0 || const_arg == folded_arg
|| COST (const_arg) > COST (folded_arg))
|| COST_IN (const_arg, code) > COST_IN (folded_arg, code))
cheap_arg = folded_arg, expensive_arg = const_arg;
else
cheap_arg = const_arg, expensive_arg = folded_arg;
@ -3772,12 +3774,21 @@ fold_rtx (x, insn)
copied = 1;
}
replacements[0] = cheap_arg, replacements[1] = expensive_arg;
for (j = 0;
j < 2 && replacements[j]
&& COST (replacements[j]) < COST (XEXP (x, i));
j++)
/* Order the replacements from cheapest to most expensive. */
replacements[0] = cheap_arg;
replacements[1] = expensive_arg;
for (j = 0; j < 2 && replacements[j]; j++)
{
int old_cost = COST_IN (XEXP (x, i), code);
int new_cost = COST_IN (replacements[j], code);
/* Stop if what existed before was cheaper. Prefer constants
in the case of a tie. */
if (new_cost > old_cost
|| (new_cost == old_cost && CONSTANT_P (XEXP (x, i))))
break;
if (validate_change (insn, &XEXP (x, i), replacements[j], 0))
break;